About that wastewater ... 📂 Archived Message Posted by Tomski on November 2, 2021, 9:26 am Perhaps London centred but easily applies to the rest of UK. Sorry about the long link https://www.newcivilengineer.com/latest/london-cannot-rely-on-new-sewers-alone-to-handle-increase-in-stormwater-01-10-2021/?eea=*EEA*&eea=WUI2bXN5L25mOUgrOFM2dHNOK0RjSEF2TUs0alBKeVJaRENMcUpIWjhIZz0%3D&utm_source=acs&utm_medium=email&utm_campaign=CONE_NCE_EDI_ALL_MONTHLY_011121&deliveryName=DM12136 London will need to find other ways to deal with the volume of water falling on the Capital during extreme weather events or face building “increasingly expensive” sewer systems, a Thames Water director has warned. Speaking at an evidence session at the London Assembly, Thames Water’s wastewater systems strategy manager Alex Nickson stated that the flooding events this summer had arguably overwhelmed the capacity at which the sewer system had been designed to cope. “There were 70 yellow weather warning forecasts this year but only two led to any real impact. If we’d setup an emergency response to all of those 70 warnings, then it would have caused inconvenience to the public and we would have been accused of crying wolf [at the problem]." Nickson argued that water management strategy may need to change as the system itself may not realistically be able to cope with the volume of rainfall in a short amount of time. He said: “Trying to place that ever-increasing volume or water underground is simply going to get incredibly more expensive. “I believe we need to try to manage that surface flooding through a varied range of solutions, infrastructure, capital flows and routing. Importantly helping make Londoners become more resilient themselves.” The Capital was hit by two major flash flood events in the summer when a large volume of rain fell within hours. Parts of East London saw flash floods with roads and TfL stations inundated with surface water. The flood events led to calls for Transport for London to reassess the viability of its flood defence measures, particularly after DLR stations at Hackney Wick and Pudding Mill Lane were hit by flood waters. Lilli Matson, chief safety, health and environment officer at Transport for London urged the Assembly to note the importance of bodies such as central government to provide funding on ensuring flood events are mitigated: "We really need to make adapting and being a resilient city an absolute priority for funding from government, we are doing all we can to transition to net zero but if we don't adapt to the changes which have already happened we won't be resilient city [...] "One of the real dangers and one we are very alert to after the July flooding is the ground height flooding... we are vulnerable to changes to the surrounding environment such as the continued paving over of London which is changing the local hydrology and so you can have surface water changes in terms of flooding in a way you wouldn't have five years ago. That is very difficult to pre-empt." Professor Jason Lowe, head of climate services at the Met Office said that summer temperatures in the UK could rise from between 1.9 degrees and 4.1 degrees in the future, with a knock-on impact on the city’s infrastructure resilience. He said: "Then in terms of the impacts that go with those. Well, for temperature, we can expect impacts on infrastructure, including energy supply and transport. We're expected impact on mortality is linked to high temperatures." The met office said it cannot pick out the trend for rainfall - and in particular flash flooding - in London from the data it has at present on UK-wide weather patterns. However Lowe didn’t rule out being able to in the future. TfL’s Matson added that the body would monitor what she deemed as more vulnerable assets more closely due to flash rainfall events in the future, particularly in terms of landslips. However she argued that the transport network held up fairly well with the influx of rain during thunderstorms in July, stating: "If we look at those events the transport network was impacted quite severely at the time, but was quite resilient, it was fully back up and running the next day. And I think that's a sort of lesson. “We haven’t seen the shock rain which places like New York, or Germany have seen but I think in terms of resilience and operational response the transport network copes with the kinds of events that have been thrown at it today.” Message Thread: About that wastewater ... - Tomski November 2, 2021, 9:26 am « Index   Searching